Q2 (a) Define the meaning of the balanced supply in the threephase system.

(b) Distinguish four (4) possible configuration of thebalanced three phase system.

(c) The line voltages applied across the life terminals of abalanced four-wire system,

star connected load are 400 V. The load impedance consists ofa 4 Ω resistor that is

in series with an inductor while the power factor of thesystem is equal to 0.75,

assume the phase sequence is RYB.

(i) Sketch the circuit diagram of the system.

(1 mark)

(ii) Calculate the phase voltages of each loads.

(iii) Calculate the phase currents that flow into eachloads.

(iv) Draw the phasor diagram of the load currents.

(v) Draw the phasor diagram of the load voltages.

(d) A balanced three-phase delta connected source suppliesline currents of 15A to a

balance three-phase star connected load, consider the linecurrent of Ia as a reference

and the phase sequence is RYB. The load in each phase iscomposed of two (2)

units of 8 + j6 Ω impedances that are connected inparallel.

(i) Sketch the circuit diagram of the system.

(1 mark)

(ii) Calculate the phase currents of the source.

(iii) Deduce the phase currents of the load.

(iv) Calculate the phase voltage of the source.

(v) Draw the phasor diagram for the phase currents, linecurrents and phase

voltages of the voltage sources.